Film feeding mechanism for camera



July 10, 1956 G. N. SMITH 2,753,775 FILM FEEDING MECHANISM FOR CAMERA Original Filed July 3, 1950 10 Sheets-Sheet l l L/ /6 I /7/ /7/ I i 7 "P /2 i 2 I a? la /8 7 E /5 /87 4 I l 606 45' INVENTOR /9 I a 6' 4 Y Gonna v 455M174 H J a I W 4 fin/"KIM? July 10, 1956 G. N. SMITH FILM FEEDING MECHANISM FOR CAMERA l0 Sheets-Sheet 2 Original Filed July 3, 1950 RM 5 m% E E W M WD D T M GW W K RQ ht QM b2 g July 10, 1956 G. N. SMITH FILM FEEDING MECHANISM FOR CAMERA Original Filed July 3, 1950 GORDON AK .jrrzc'f/g July 10, 1956 G. N. SMITH FILM FEEDING MECHANISM FOR CAMERA l0 Sheets-Sheet 4 Original Filed July 3. 1950 INVENTOR. 6 17270 4 J0: l Z L July 10, 1956 G. N. SMITH 2,753,775

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KFOA/ JM/IA BY l0 Sheets-Sheet 10 2,753,775 FILM FEEDING MECHANISM FOR CAMERA Gordon N. Smith, Portland, Greg, assiguor to Sawyers Inc., Portland, Greg, a corporation of Oregon Original application July 3, 1950, fierial No. 171,863, now Patent No. 2,680,400, dated June 8, 1954. Divided and this application May 19, 1952, Serial No. 288,595

Claims. (Cl. 95-61) My present invention relates to stereoscopic cameras and to certain improvements in camera mechanisms, particularly relating to stereoscopic cameras but in some instances being applicable to conventional cameras for taking single exposures. This application is a division of my copending application Serial No. 171,863, filed July 3, 1950, now Patent No. 2,680,400, issued June 8, 1954.

The principal object of the present invention is to provide a camera capable of producing stereoscopic transparencies for use in viewing or projecting devices. While not necessarily limited thereto, the invention is particularly adapted for producing stereoscopic pairs of transparencies which may be mounted in discs adapted to be rotated step by step in a stereoscopic viewing device such as disclosed in the patent to Gruber, No. 2,189,285, or to be rotated step by step in a projecting device designed to project enlarged single or paired images on a distant screen. Also, while not necessarily limited thereto, the invention is particularly adapted to produce stereoscopic pairs of transparencies in a film strip of such relative dimensions that each transparency may be surrounded by a marginal portion including an elongated tab at one end whereby the transparencies may be mounted in a pocketed reel such as disclosed and claimed in the copending application of Kurz, Serial No. 23,113, filed April 24, 1948, now Patent No. 2,571,584, issued October 16, 1951, thus enabling the owner of the camera to produce his own reels of transparencies.

A further object of the present invention is to provide a camera which produces exposures in a film strip, the camera being of such character as to produce two rows of exposures longitudinally of one film strip. Correlated with the foregoing object is the object of providing film strip feeding means adapted to feed a strip of film step by step between exposures in one direction while taking the first row of exposures and step by step in the opposite direction while taking the second row of exposures in order that the completely exposed film strip will be rewound into the cartridge in which it was originally contained when completely exposed.

A further object of the present invention correlated with the foregoing is to provide film advancing mechanism capable of moving film in either direction, by the use of one manual knob, while maintaining the film in taut condition between a cartridge and take-up spool regardless of the increasing or decreasing eifective diameter of the roll of fihn on the shaft of the cartridge or the shaft of the take-up spool.

A further object of the present invention is to provide means whereby a film may be advanced step by step for any predetermined, variable distance in accordance with the preselected setting of a limit mechanism. In order that films of various lengths may be employed in the same camera, the limit mechanism may be set to prevent further step-by-step movement of the film in the first direction until shifting of the lenses to the position for taking the second row of exposures has been accomnited rates Patent Patented July 10', 1956 ice 2 plished. Such shifting simultaneously shifts certain portions of the film advancing mechanism to prohibit further advancing movement in the first direction and permit step-by-step retraction of the film in the second di rection.

A further object of the present invention is to provide improved shutter blade timing mechanism in combination with improved shutter blade and timer resetting mechanism.

A further object of the present invention is to provide improved means whereby a wide film strip may be provided with a narrow leader extension adapted to be inserted in a slot in a take-up spool without requiring winding of the narrow leader strip past the rear surfaces of the light tunnels prior to closing the camera casing, in order that a rigid loading sequence need not be observed. As a comment on the foregoing, it is to be observed that a rigid loading sequence is desirable in order that a person may avoid attempting to take exposures on the exposed leader strip, but the camera will operate even though this measure should be overlooked.

A further object of the present invention is to provide an improved film cartridge loading arrangement whereby the cartridge engaging and driving spindle remains fixed in position and the cartridge is inserted longitudinally and coaxially of the cartridge engaging and driving spindle, the case of the camera including means for permitting loading of the cartridge through the bottom of the camera when the rear cover is open.

A further object of the present invention is to provide improved film advancing mechanism including a combination of slip and ratchet clutches.

Reference is herein made to my prior Patents 2,515,272, issued July 18, 1950, 2,553,015, issued May 15, 1951, and 2,557,478, issued June 19, 1951, for more complete disclosure of certain portions of the present invention, or for a better understanding of certain portions of the present invention by reference to the foregoing patents which may disclose variations of certain portions of the presently described mechanism.

The objects and advantages of the present invention may be more fully ascertained by inspection of the following specification taken in connection with the accompanying drawings wherein like numerals refer to like parts throughout, while the features of novelty will be more distinctly pointed out in the appended claims.

In the drawing, Fig. 1 is a front view of a stereoscopic camera made in accordance with the present invention;

Fig. 2 is a plan view of the camera disclosed in Fig. 1;

Fig. 3 is an end view taken from the left end of Fig. 2;

Fig. 4 is an end view taken from the right end of Fig. 2;

Fig. 5 is a partial rear view of the frame illustrating a portion of the film feeding mechanism;

Fig. 6 is a partial view taken substantially along line 6-6 of Fig. 6;

Fig. 7 is a view in elevation of the inside of the hinged rear cover illustrating the pressure pads and film guiding means, the cover being illustrated as it would appear when removed and turned over about its longitudinal axis;

Fig. 8 is a sectional view looking down across the rear cover, the view being taken substantially from the plane of line 8-8 of Fig. 7;

Fig. 9 is a partial view of the inside of the front cover and the portions of the mechanism mounted thereon including a selector plate, a pair of shutters and a fiash switch device, the selector plate being in position to per mit exposure of the lower row of exposures;

Fig. 10 is a view looking up on the mechanism disclosed in Fig. 9, the view being taken from the direction indicated by the line 101t) of Fig. 9;

Fig. 11 is a partial view looking at the front of the frame and mechanism mounted thereon including the shiftable lens assemblies, portions of the film advancing mechanism, the shutter reset and late ng mechanism and the shutter timing mechanism, the lenses being elevated to take the upper row of exposures, and the shutter mechanisms being cocked;

Fig. 12 is a partial, sectional view looking down substantially along the plane of the line 12-32 of Fig. 11;

Fig. 13 is a partial, sectional view looking down substantially along the line 13-13 of Fig. ll;

Fig. 14 is a sectional View looking down from the plane of the line 14 14 of Fig. 11 and illustrating the timer cam and escapement mechanism on an enlarged scale;

Fig. 15 is a view in elevation of the selector plate alone;

Fig. 16 is a view in elevation of the inner shutter alone when the inner shutter is released, the selector plate and inner shutter being in vertical alignment corresponding to the superimposition thereof illustrated in l 9;

Fig. 17 is a view in elevation of the outer shutter alone in the released. position corresponding to Fig. 9;

Fig. 18 is a partial view, on an enlarged scale, of the flash synchronizer switch when the shutters are cocked, illustrating the safety fea ure thereof for preventing accidental discharge of a flash bulb;

Fig. 19 is a view corresponding to Fig. 18 with the parts in the relative positions assumed when the trip has been almost entirely actuated, immediately prior to release of the shutter blades;

Fig. 20 is a horizontal section showing the cable release pin with a release cable attachment associated therewith, the view being taken substantially along line 2-2il of Fig. l and being on an enlarged scale;

Fig. 21 is a partial, sectional view illustrating the means for associating a flash gun with the camera and the contact connecting the flash gun to the flash switch taken substantially along line 21-21 of Fig. 2 and being on an enlarged scale;

Fig. 22 is a View looking up at the hinged end of the case with the cover opened to sufficient extent to permit the insertion of a cartridge and the association of the film strip leader with the take-up spool;

Fig. 23 is a schematic View of a portion of a film strip illustrating the exposure sequence for stereoscopic pairs;

Fig. 24 is a somewhat schematic view in elevation illustrating a film leader strip of narrow width associated with one of the light tunnels;

Fig. 25 is a vertical section taken substantially along line 2S25 of Fig. 24;

Fig. 26 is a vertical section taken through the view finder and spirit level substantially along line 26-2 of Figs. 2 and 21;

Fig. 27 is a partial view of the back of a pocketed reel formed for reception of transparencies produced by the camera; and

Fig. 28 is an enlarged vertical section taken substantially along line 2823 of Fig. 1.

For simplicity each portion of the camera is described under an appropriate subheading.

Frame and casing The camera comprises an interior frame generally designated by the number 19. The frame is enclosed within a casing consisting of four separable parts including a front cover 11 which is secured to the frame and a rear cover 12 which is hingedly connected to the front cover and bottom at 13 and held in closed relation thereto by a tongue 14 at the end opposite the hinged end, the tongue having a rectangular opening 15 therein adapted to snap over a rectangular lug 16 on the front cover, the lug being disposed within a rectangular depression 1'7 to prevent accidental release of the rear cover. When it is desired to load or unload the camera the resilient tongue 14 is released by inserting the fingernail between the bottom of the depression 17 and the tongue 14 whereupon the rear cover may be swung to one side about the hinge 13. The top of the case comprises a part 18 which is secured to the top of the frame, and the bottom of the case is provided by a part 19 which is secured to the bottom of the frame it It is to be appreciated that the portions 11, 18 and 19 are detachably secured to the frame in any convenient manner. the means for securing the same being in part relatively inaccessible so as to prevent disassembly of the camera except in the hands of an experienced, trained person. Not all of the attaching means are illustrated, but sufficient are herein illustrated to disclose the principal features thereof. For example, in Fig. 9 there are illustrated a pair of screw receiving bosses 29 adjacent the vertical flange 33 and which are adapted to receive screws passing through an end flange (not illustrated) of the frame 1 the heads of the screws being accessible when the rear cover 12 is swung open. Also, in Fig. 11 a pair of openings 21 are illustrated in an end flange projecting from the opposite end of the frame 1% through which screws pass into the threaded screw receiving bosses (not illustrated) in the opposite end of the front cover ill, the heads of the screws therein mounted being accessible when the rear cover 312 is swung open.

The top cover 18 is interlocked with the front cover Tl so as to prevent leakage of light and must be removed before the front cover can be removed even though the screws heretofore mentioned have been removed. The top cover is held in place in part by a pair of screws having their heads engaged beneath pairs of lugs 22 (Fig. 9) projecting inwardly from the front cover 11, and engaged with threaded openings (not shown) in the bottom of the top cover, the screws being accessible by of long, narrow screw-drivers inserted from the bottom alongside of the shutters after the bottom cover has been hand ..d. The top cover is also held in place in part by screws (not shown) passing downward through the top cover into threaded openings in the frame as indicated at 23 (Fig. 12). Therefore, in order to remove the top cover the bottom cover has to be removed first, the bottom cover being attached by means of screws 2 (Fig. 22) accessible from the outside of the bottom cover, passing through openings therein, and being received in threaded open ings 25 in the rear of the frame it? l3) and threaded openings 26 (Fig. 10) in the bottom of the front cover, the openings 26 extending into Inns 2'? 9). It is apparent from the foregoing that even hough the bottom cover should be removed it would require expert knowledge completely to remove the casing to expose all of the mechanism.

Light is excluded from the interior of the by light-trapping, interfitting on the parts and the frame. For the most part description of such interfitting flanges will be omitted, since the provision thereof is standard practice well known in the art. However, it is to be remarked that the frame it? is preferably ovided with a groove 3% (Figs. 5 and 1]) in which a (Fig. 7) on the hinged rear cover fits, and that the hinged rear cover is also provided with a flange 3?. which fits into a groove provided between adjacent edge portions of the frame and of the bottom cover 1% when the bottom cover is in position. The front cover has an inwardly projecting, vertical flange 33 (Figs. 9 and 10) adjacent the lug L5, the outer face of which is beveled in order to engage the inner beveled face of a corresponding flange (not shown} on the free end of the hinged rear cover 12. The hinged end of the rear cover comprises a portion 34- (F which is rolled inwardly to provide a holder for a vertica rod having its ends projecting beyond the cover to provide the pintles 3S and 36 of the hinge 13. The upper pintie 35 is receivable in a socket (not shown) in the top cover 13 and the lower pintle 3a is receivable in a correspond ing socket (not shown) in the bottom cover 1%. When the bottom cover is removed the hinged rear cover may be swung open and moved downward to disengage the pintle 35 from its socket. A light shield plate 38 is mounted adjacent the pintle-retaining portion 34, the two being held together by rivets 39, the enlarged heads of which project into the cartridge receiving space to form a spaced pair of locating pads to prevent the cartridge from more than a limited amount of relative freedom in the cartridge receiving space. The end of member 33 adjacent the pintle is spaced from the portion 34 to provide a vertical groove 43 into which a flange on the adjacent end of the front cover (not shown) projects when the rear cover is swung shut. The flange 32 is of relatively narrow width across the rear of the camera, but adjacent the hinged end the flange is enlarged to provide a cartridge supporting shelf 41 which fits into a continuation of the groove between the bottom cover and the bottom edge of the frame when the rear cover is swung shut in order that a cartridge, indicated in schematic outline in Fig. 8, may be supported in the cartridge receiving space 42 (Figs. 5 and 13) in the frame 16, the upper end and inner surface of the cartridge receiving space being formed in the frame itself. The bottom cover is provided with a large open notch 43 (Figs. 3 and 22) forming a continuation of the cartridge space whereby a cartridge may be inserted longitudinally from the bottom of the camera when the rear cover is swung open. The upper end of the cartridge is thus moved longitudinally into engagement with the cartridge engaging and driving spindle 44 (Figs. 5 and 6) which is provided with a forked lower end in accordance with usual practice. After the cartridge is inserted, and prior to closing of the hinged rear cover, the film leader strip is stretched across the rear of the frame and the tip thereof is hooked into a vertical slot 45 (Fig. 5) in the outer shell 46 of a takeup spool journaled in a take-up spool space 47 at the opposite end of the frame. The shell 46 is pressed onto an enlarged diameter of a hub portion 48 which may be manually rotated as will appear so that the film may be wound onto the take-up spool or released therefrom in accordance with the manipulation of a film advancing knob 56. In either direction of movement the film is guided between an upper flange Eli and a lower flange 52 on the frame iii, movement of the film being effected by a spaced pair of sprockets 53 fixed to a sprocket hub 54 and retained in a sprocket recess 55 in the frame It). The hub 54 is fixed to a vertical shaft 56 by means of setscrews 57, the shaft projecting through the top of the frame and being fixed to a horizontal, sprocket shaft driving gear 53. When the film strip has been firmly engaged the rear cover may be closed.

Picture sequence As indicated more or less schematically in Figs. 23, 24 and 25, the present invention is designed for use with 35 mm. film strip, the film strip 61 having upper and lower perforations 61 therein for engagement with the sprockets 53 and the clear space between the perforations being such that a lower row of approximately 16 mm. exposures may be taken, followed by an upper row of approximate ly 16 mm. exposures, with clear space between the exposures and between the upper and lower rows so that each exposure may have a margin surrounding the same when out from the film strip to permit insertion of the views in a holding reel such as disclosed in the abovementioned Kurz patent. In order that the upper and lower rows of exposures may be taken, the frame is provided with a spaced pair of light tunnel clearance holes 63 (Fig. 5), one at each side of the sprocket recess, and a spaced pair of light tunnels 64 are guided by guide posts 210 and 213, and guide posts 139 and 21?, respectively, in the clearance holes for movement between upper and lower extreme positions. Each of the light tunnels is provided with an upper, inwardly beveled rail 66 (Fig. and a lower, inwardly beveled rail 67, both rails projecting a few thousandths of an inch beyond the vertical faces of the frame 10 so that the film surface rides on the accurately machined outer edges of the rails, thus locating the film in exact relation to the lenses 70.

It will be noted that the open space surrounding hub 4-8 (Fig. 5) inside of the shell 46 on the take-up spool is a lesser height than the distance between the guiding flanges 51 and 52 but is sufficiently high to provide a slot 45 long enough to accept the relatively narrow film leader 71 (Fig. 24). The beveled inner edges of the rails 66 and 67 (Fig. 25) are provided to prevent the light tunnel rails from catching the edges of the film leader strip when the light tunnels are shifted over the narrow film with the camera back closed. This provision eliminates the necessity for a rigid loading sequence. After the rear cover has been closed and the entire fogged leader portion of the film has been wound past the second light tunnel, the camera may be operated to expose spaced pairs of stereoscopic transparencies as follows.

The centers of the lenses and light tunnels are spaced apart by the average interpupillary distance of about 65 mm. so that upon the first exposure a pair of stereoscopic transparencies '75 will be produced as seen in Fig. 23, Fig. 23 being a view looking at the back of the film when the film is in the camera. It will be seen that between the right and left exposures there is sufficient room for two more exposures to be taken, but the advancement of the film is such that each movement advances the film twothirds of the distance between the centers of the left and right exposures so that the second exposure produces a stereoscopic pair indicated by the numerals '76, there being an unexposed blank between the right exposures of the first and second pairs. The third exposure will, however, occur in such position that none but the second is wasted. The sequence of transparencies is as follows: Right 1, blank, Right 2, Left 1, Right 3, Left 2, Right 4, and so on. When the proper amount of film has been fed onto the take-up spool, the feeding direction is reversed, the light tunnels raised into position to take the upper row of exposures, and the film rewound onto the cartridge. At the end of this return movement there will be one blank space, as indicated in Fig. 23, between R36 and R37.

Film of the character described is usually supplied in cartridges containing suflicient film for twenty 33 mm. frames, and will provide twenty pairs of approximately 16 mm. exposures in each of the upper and lower rows, or in cartridges containing suflicient film for thirty-six 35 mm. frames, which will provide thirty-six pairs of approximately 16 mm. exposures in each of the upper and lower rows. The film advancing knob 56 (Fig. 2) is provided with a corresponding plurality of indicia movable past a fixed pointer on the top of the camera. In order to prevent unwinding of the entire length of film from the cartridge, the film advancing knob may be set at a selected position prior to taking the first exposure as follows:

The hub 43 (Figs. 5 and 6) is loosely journaled upon a central shaft 81 which extends beyond the shell 46 at its upper and lower ends, the lower end being journaled in a socket (not shown) in the bottom cover 19 and the upper end projecting through the top cover 18. The shaft 81 is loosely journaled within the hub 48 so that it may be moved longitudinally or rotationally, and the knob 50 is fixed to the shaft by a setscrew 8-i- (Fig. 1) so as to rest upon the upper end of a collar 85' fixed to shaft 81 and slidably and rotationally journaled in a bearing in the upper cover 18. The knob is normally maintained against the upper cover by a curved washer spring 86 surrounding the collar 85 and bearing against the lower surface of the upper cover. The spring 86 bears against a film advance stop 90 fixed to the upper surface of a clutch pinion 91 pressed onto the shaft 81. When the knob St) is pulled by a force stronger than the pressure of the spring 86, the pinion 91 is slid out of engagement with the teeth of an idler gear 92 loosely journaled on a stub shaft 93 projecting upwardly from the frame. The idler gear 92 is provided with an oppositely disposed pair of upwardly pro jecting abutment pins 94 which normally rest in alignment with the centers of the sprocket gear shaft 56 and the take-up spool shaft 81 (Fig. 6). When the pinion 91 is 7 elevated by pulling knob 50 upward, the portion of the stop 9t? which might engage one or the other of the pins 94 may be rotated above the tops of the pins so that the take-up knob may be freely rotated to any selected position.

As seen in Fig. 2, the indicia on knob 50 include three boldly indicated indicia numbers, namely 1, 19 and 35, the numeral 1 being directly over the tip of stop 9tl. When a twenty-exposure-35 mm. film is used, the exposed leader portion is first wound onto the take-up spool by advancing the film strip three times in the manner to be explained; then the knob 56? is elevated and rotated to bring the numeral 19 opposite the indicator 80. Similarly, when a thirty-six-exposure film is used, t .e numeral 35 is placed opposite the indicator $9. The advancing movement between frames is accomplished by manual rotation of the knob 5% which drives the sprocket gear 53 a half revolution through pinion 91 and idler gear 92. The gears 58 and )2 are provided with eighty teeth and the pinion 91 is provided with one more than half that number, or forty-one teeth, so that stop 9% moves back one tooth toward pin-engaging position during each feeding movement. When nineteen or thirty-five exposures have been made, as the case may he, the numeral 1 comes back to the indicator 8% at the same time that the stop 5 8 rrives in such position as to prevent further winding of the film onto the take-up spool due to the engagement of the stop with one or the other of the abutment pins 94. The operator then knows that he must shift the light tunnels to the upper position and thereafter rotate the knob 50 in the opposite direction until the numeral 19 or 35 reaches the indicator again in the reverse direction.

Fig. 23 discloses the picture sequence on a twenty-exposure-35 mm. film strip, it being apparent from examining the right and left exponents that thirty-seven expo-sures may be made, nineteen in the lower row and eighteen in the upper row. As previously explained, there will be a blank between Right 1 and Right 2, and it will likewise be apparent that there will be a blank between Left 18 and Left 19 since the stop Qt; engages the abutment pin 94 at this point to prevent further advancement of the film in the initial direction. The operator must now elevate the light tunnels and start turning the knob 5-3 in the opposite direction as indicated by the arrows. Since the film advancing and shutter resetting mechanism are tied together, as will presently appear, no exposures can be taken in the spaces immediately above Right 19 and Left 19, since the film must be advanced in order to reset the shutters after having taken the ninteenth pair of exposures. Accordingly, the twentieth pair of exposures will occur above the eighteenth of exposures, then the next advancing movement will cause another blank space to be left since the twenty-first pair of exposures will be above the seventeenth. A careful operator will observe the fact that the index numeral 19 on knob 5% will be opposite the pointer bit when he takes the thirty-seventh pair of exposures, and will thereafter successively advance film and release the shutters without attempting to take further pictures since the exposed leader portion will now be behind the lenses, thus leaving a blank above the first blank which initially occurred between Right 1 and Right 2. Altogether, on a twenty-exposure-35 mm. film strip there will be six blanks, as clearly shown in Fig. 23. Likewise, in a thirty-six-exposure-35 mm. film strip there will be the same number of blanks and there will be thirtyfive pairs of exposures in the lower row and thirty-four pairs of exposures in the upper rot It is to e appreciated that the knob 53 may be set at any initial position so that if an operator wishes to take eight pairs of exposures, for example, he may set the eighth division on knob 5%) opposite the pointer when taking the initial exposure and the stop 90 will come back to one of the abutment pi. s 94 when the eighth pair is exposed, thus reminding the operator that he has taken the number of exposures he wished to take and to shift the light tunnels and wind film in the opposite direction. Likewise, it is not necessary to continue winding film in the first direction until the entire strip has been exposed even though the knob 5% has been i. lly for such, as reversing movement may be accom lished at any time upon shifting the Winding mechanism.

When the film is to be wound out of the cartridge to take the lower row of exposures means are provided to prevent winding of the film in the reverse direction, as will appear, and vice versa.

Film advancing mechanism The knob 50 is rotated counterclockwise (Fig. 6) to advance the film strip from the cartridge. Rotation of the take-up spool is achieved through the medium of a spool driving pinion ltil) (Fig. 5) which constantly meshes with the idler gear 92, the pinion 1% having the same number of teeth as the clutch pinion 91 so that at each half revolution of the sprocket driving gear 58 and the sprockets 53 the take-up spool makes slightly less than one revolution, provided it rotates coextensively with the pinion 1th Positive metering of the film is achieved through the sprockets 53 which are rotated exactly one-half of a revolution at each feeding movement, limitation thereof to one-half of a revolution being achieved through means to be described later. The eifective diameter of the take-up spool is such that when it is practically empty one revolution will wind up slightly more film than the amount fed forward by the sprockets 53. Therefore, means must be provided to permit the take-up spool to rotate to a lesser extent that the driving pinion 109 in varying degrees as the size of the roll of film upon the shell 46 increases, the means being described as follows: The hub 48 of the take-up spool is provided with several steps of increasing diameter, the face of the upper one supporting the pinion 190. The pinion 1% is loosely journaled upon shaft hit for relative rotational movement with respect to a disc lill fixed to the upper one of these steps. On the next lower step of the hub there are loosely journaled a friction pad N9 and a pawl mounting plate 192 which is held in friction contact with the friction pad by a spring washer 103 bearing against the lowest step. The plate 192 has an upwardly extending, curved arm 104 thereon which anchors one end of a spring 196, the other end of the spring engaging the free end of a dog m7 pivotally mounted on a pin 1638 rising from the plate 1%. Spring 1% urges dog 107 into engagement with the teeth of the pinion in such manner as to permit clockwise rotation of the pinion lit-ll independently of the plate 1G2, but counterclockwise rotation of the pinion 10% results in corresponding movement of the plate 192. When the plate 1% is driven counterclockwise the take-up spool will be urged by friction washer 9 to rotate in the direction to wind film thereonto as it is fed forward by the sprockets 53. Since the take-up spool normally tries to wind up more film than is payed out by the sprockets, the friction clutch arrangement provided by the disc fill, friction pad 1&9, plate 162 and spring washer 103 permits the take-up spool to slip while the film is constantly maintained in taut condition between the take-up spool and the sprockets.

When the lenses are shifted to the upper position and the film is being wound in the reverse direction by rotating the clutch pinion 91 clockwise, the spool pinion 1% will also rotate in the clockwise direction since it is connected thereto through the teeth of the idler gear 92, but the dog 167 will ride over the teeth of pinion 1% and the plate 102 will rotate more slowly with the take-up spool as it is pulled in the reverse direction by the sprockets 53. The dog and friction clutch prevent the take-up spool from being rotated due to the film trying to straighten itself.

The cartridge engaging spindle 44 is loosely journaled in a sleeve 116 having an annular head 111 thereon which is provided with a step on its upper surface loosely journaling a second pawl mounting plate 112, this plate being similar to plate 102 but mounted in the reverse direction so that a spring mounting arm portion 113 extends downwardly to anchor one end of a pawl spring 114 which is engaged with a dog 115 pivotally mounted on a pin 116 depending from the plate 112. A friction washer 117 is pressed against the upper surface of plate 112 by a spring washer 1118 held in position by a pin 119 extending transversely through a hole in the spindle 44 and resting in a slot 120 in the spring washer so that the washer must rotate when the spindle 44 is rotated. The sleeve 110 loosely journals a spindle pinion 125 which constantly meshes with a second idler gear 126 loosely journaled upon a stub shaft 127 extending upwardly from the frame. The gear 126 is provided with eighty teeth, the same number as gears 58 and 92, and the pinion 125 is provided with one more than half that number, or forty-one, teeth as is the case with pinions 91 and 100.

When the knob 50 is rotated counterclockwise to wind onto the take-up spool film which is being advanced by the sprockets 53, the chain of gears provided across the top of the frame likewise rotates the pinion 125 in the counterclockwise direction, the pinion revolving slightly less than a complete revolution at each semi-revolution of the sprockets 53. Rotation of the spindle 44, however, is solely accomplished by the sprockets 53 drawing the film from the cartridge as the dog 115 rides over the teeth of pinion 125, to the least extent when the cartridge is full and to a progressively increasing extent as the cartridge empties. The dog and the friction disc 117 prevent excess unwinding.

When the lenses and light tunnels have been elevated and the film is to be wound back into the cartridge, the knob 50 is turned clockwise so that the pinion 125 and spindle 44- are driven clockwise in the direction to wind film into the cartridge. The dog acts positively to drive the plate 112 in the clockwise direction to the same ex tent that the pinion is driven but the friction clutch permits the spindle 44 to slip to an increasingly greater extent as the diameter of the roll of film in the cartridge progressively increases.

Film metering and direction of advance control Means are provided directly beneath the gear 58 and the idler gears 92 and 126 whereby rotation in either direction is limited to one-half of a revolution of the sprockets 53 and whereby the film may be drawn out of the cartridge only when the lenses are down and wound back into the cartridge only when the lenses are up. As will be seen in Fig. 12, the sprocket gear shaft 56 extends through one end of a pair of longitudinal slots 13!) in a superimposed pair of longitudinally movable limiting slides 131, the opposite ends of the slots 131 being guided by the idler gear shaft 93 (Figs. 11 and 12). The ends of the slides 131 adjacent shaft 93 rest upon a shoulder 132 on the shaft and may cant thereabout in the longitudinal direction depending upon the extent to which a spring 133 surrounding shaft 56 is compressed, the spring 133 normally maintaining laterally and upwardly extending wings 134, one on each of the slides 131, up against the lower surface of the sprocket gear Each of the wings 134- is successively engaged by one or the other of a pair of stop pins 135 projecting downwardly from gear the pins being diametrically opposed to each other. Each slide is provided with a lateral arm 136 which is engaged by one end of a spring 137 extending toward the take-up spool end of the frame, the springs being anchored, one to a lug 138 at the back of the frame and one to the upper end of a long light tunnel guide 139 mounted in the front of the frame, the springs tending to retain the slides in superimposed relation with the ends of the slots 131) against the shaft 56 as illustrated in Fig. 12. In order that the spring 133 may operate without interference, it

-10 bears against a flange 140 on a sleeve 141- surrounding shaft 56, the flange being in contact with the lower slide.

The sides of the slots a re outwardly notched as indicated at 144 and 145, the notches being of suflicient size to permit partial rotation of a slide lock 146 on the upper end of a slide locking shaft 147, the slide lock being movable from the position illustrated in full line in Fig. 12 to the position illustrated in dash line in the same figure. When the lock is partially rotated out of longitudinal alignment with the gear train shafts so as to engage the shoulders provided by the notches 144 as shown in full line, the slides are both locked against longitudinal movement and the gear train is likewise locked since both of the stops are in engagement with the wings 134 on the slides. The lock 146 is rotated to the locking position when a film advancing movement is being made and the shutters are being cocked, as will be explained later.

When the shutters are tripped to take an exposure the lock 146 is automatically rotated into alignment with the gear shafts as shown in dash lines, thus permitting longi tudinal movement of the slides to the extent that the slots 13%? extend beyond stub shaft 93 as seen in Fig. 12. Such longitudinal movement occurs when the knob 50 is rotated, whereupon the gear 58 moves either one of the slides through the stop 135 engaging wing 134. It will be apparent that the stop 135 will pass beyond the tip of the driven wing 134 when the gear 58 has rotated about twenty degrees, whereupon the slide 131 which has been moved from its normal position is snapped back by the spring 137 into position to engage the opposite stop 135 when it has completed half a revolution. At a portion of a revolution of gear 58 beyond this point the shutter and timer resetting mechanism causes lock 146 to move back to locking position so that rotation of gear 58 will be limited to one-half a revolution. The stop 135 which has moved one of the slides must pass over the wing 134 of the other slide in order to permit completion of the half revolution, and for this purpose each slide wing is bent upwardly to provide a ramp for the bottom of stop 135 which cams the side wing 134 downwardly as permitted by the spring 133, the wing 134 snapping up behind the stop as soon as the half revolution is completed. The slides are now locked between the lock 146 and the shaft 56 so that rotation of shaft 56 in either direction is prevented.

In order that film may be drawn out of the cartridge only when the lenses are down and wound into the cartridge only when the lenses are up, a shift lock plate (Figs. 11 and 12) is pivotally mounted upon an enlarged lower shoulder of the stub shaft 127 on which the idler gear 126 is mounted, the gear having a large lower hub to retain the plate. The shift lock plate 155 is provided with a pair of stop fingers 156 which straddle a lug 157 on the frame 10. When one of the fingers bears against one side of the lug a vertical flange 158 on the shift lock plate is aligned with the end of one of the slides 131 as seen in full line in Fig. 12, and when the other finger bears against the opposite side of the lug the flange 158 is aligned with the end of the other slide 131 as seen in dash ine in Fig. 12. The plate supports one end of a shift lock plate spring arm 1611, made of spring wire, which extends forward beyond the frame 10 and engages in a rectangular notch 161 in an upwardly extending portion of a selector plate 162 (Figs. 9 and 15). The selector plate is movable longitudinally from one extreme position illus trated in full line in Fig. 9, when the lower row of pictures is to be taken, to the opposite extreme position illustrated in dash line in Fig. 9, when the upper row of pictures is to be taken. The spring arm 16:) engages one or the other end of the slot 161 when the selector plate is being shifted to shift and hold the flange 158 in the desired position. Thus, when film is to be unwound from the spool, one of the slides 131 is blocked, preventing the gear 58 from being turned in the wrong direction so that the knob 51 may be turned only in the counterclockwise direction 11 (Fig. 6). When the lenses are shifted upwardly and the selector plate moved to the opposite extreme position the other slide is blocked and the knob may only be turned in the clockwise direction for rewinding the film into the cartridge while the upper row of pictures is being taken.

Selector plate and lens shift The selector plate 162 mentioned above is a thin sheet metal plate stretching across the front of the camera behind a pair of large windows 170 (Fig. l), the centers of which are spaced apart approximately the average interupupillary distance of 65 mm., the windows being closed by optically clear glass mounted in slightly projecting window frames 171, the rims of which are threaded for mounting filter retainers (Fig. 28). The selector plate (Fig. l5) is provided with a lower pair of apertures 172 in horizontal alignment and spaced the same distance as the windows Fill, the apertures being of sutlicient size to permit the maximum amount of light through similarly spaced lenses 7% when aligned therewith while the lower row of pictures is being taken. The selector plate is also provided with an upper, horizontally aligned, offset pair of apertures 173 spaced apart by the same amount for registry with the lenses when in the upper position. The selector plate is longitudinally guided by turned steps on a pair of studs 174 (Fig. 9) guiding the upper edge thereof and by turned steps on a pair of studs 178 (Fig. 10) guiding the lower edge thereof, the upper edge of the plate being retained between the step shoulders 176 of the studs 174 and a selector plate retainer strip 177 mounted on the studs 174. The lower edge of the selector plate is retained between the step shoulders of the shutter studs 178 and a lower selector plate retainer strip 1239, held in place by screws 175, so that the selector plate may be moved longitudinally from a position such that one or the other pair of apertures therethro-ugh is in alignment with the lenses.

Movement of the selector plate is effected through a selector knob 181 on the front of the camera between the windows 170, the knob being provided with appropriate directional arrows and indicia to indicate the direction of rotation of the knob to shift the lenses. The knob is fixed to the end of a shaft 182 which extends through and is journaled in the front cover 11. Milled in the shaft is a selector plate shifting pinion 183, the teeth of which are engaged with rack teeth 185 on the lower edge of an elongated slot 186 in the central portion of the selector plate, whereby as the knob 181 is rotated 130 degrees the pinion and rack longitudinally shift the selector plate. A partial cap 187 covers the lower portion of the front of the knob 131 so that one or the other of the pair of directional arrows thereon will be hidden in order that the operator will be saved confusion and may tell at a glance which direction the knob may be rotated.

The inner end of shaft 182 is fixed to a lens shifting lever 19% having a crank pin 191 thereon which extends into a slot l92 (Fig. 11) in a lens shifting yoke 193 extending horizontally across the front of the frame. The opposite ends of the yoke 193 are provided with forks which embrace pins 194 on the adjacent edges of the light tunnels 64-, the pins projecting forwardly from lugs on the adjacent forward edges of the tunnels. Each of the pins 194 is also engaged in the outer forked end of an arm of a lens shifting sector gear US, the gears being pivoted on fixed bosses 196 of the frame 1%, the inner a jacent ends of these arms being provided with gear teeth whereby movement of the pins 194 in unison in a vertical direction is assured. A coaxial extension 2% of shaft projects forwardly in position to engage in a journal opening 201 in a plate 292 overlying the meshed sector gears and the shifting yoke and mounted on the frame by a pair of screws 203, so that the inner end of shaft 132 is rigidly maintained against play. The crank T91 moves about the curved outer edge 205 of the plate 2 52 as the crank arm 190 is rotated through 180 degrees.

One of the light tunnels 64 is provided with a forwardly projecting guide fork 209 which is fixed to its lower surface and projects laterally to embrace a short guide post Zlil mounted in lugs extending from the front wall of the portion of the frame defining the cartridge receiving space and retained by screw 213. The inner end of the opposite side of the light tunnel 64 is provided with a pair of laterally projecting guide sleeves 212 which embrace vertically spaced portions of a long guide post 213 mounted in the frame 10 and retained by screw 21 i (Fig. 12). The opposite side of the other light tunnel is provided with a forwardly and laterally projecting guide fork 215 at its upper front corner which embraces the upper part of the guide post 139 to which the spring 137 is attached as previously noted. The opposite rear corners of this light tunnel are provided with a pair of guide sleeves 216 which project laterally and embrace a guide post 217 fixed in the frame 16. Each of the light tunnels is therefore guided on diagonally positioned, vertical posts, each guide tunnel having two portions totally embracing one of the posts and a third diagonally positioned guiding portion partially embracing the other post. This effects a three-point guiding means for precise, easily machined and easily aligned assemblies. Each of the light tunnels is provided with a pair of oppositely projecting upper and lower limiting screws 218 which may be adjusted to en gage portions of the frame It to limit vertical movement of the light tunnels in either direction so as to align them optically with the film exposure areas, thereby properly fixing the positions of the rows of exposures with respect to the edges of the film as it is being guided between the flanges $1 and 52 on the frame it).

The end of the slot 192 in shifting yoke 11% in vertical alignment with the journal opening 251 is provided with a pair of vertically extending upper and lower detent notches 229 into which the crank pin 1% snaps at the limit of its movement, thereby frictionally locking the light tunnels against accidental displacement from correct positions for taking the two rows of pictures. The yoke is made suficiently resilient to bow vertically as the crank pin 191 attempts to move the tunnels to a greater extent than permitted by screws 218. Considerable force is required to spring the yoke arm 193 as pin 191 leaves the detent notches 220.

Shutters and shutter reset mechanism The shutters are partially disclosed in Figs. 9 and 10 in superimposed relation in released position, and are shown alone in Figs. 16 and 17, oifset vertically from each other in the same relative positions occupied in Fig. 9 and in the same relative position with respect to the selector plate 162 illustrated in Fig. 15. The shutters comprise a rear shutter 225 having for the most part a straight upper edge broken only by a spring anchoring tab 226 to which one end of a shutter actuating spring 227 is fixed, the other end of the spring being anchored to a pin 228 at the end of the front cover 11. The longitudinally straight upper edge of the shutter is guided in guide grooves in the studs 174, which are similar to guide grooves in studs 178 fully illustrated in Fig. 10. One of the lower studs 178 guides a lower longitudinal edge portion 229 of the rear shutter and the other stud 178 fits a slot 23% in the lower portion of the rear shutter. The shaft 132 of the selector plate shifting mechanism passes through a central horizontal slot 231 so that the rear shuter may slide longitudinally from its cooked or set position to the released position as urged by the spring 227. The rear shutter is provided with a horizontally spaced pair of lower apertures 232 having rounded right ends and squared left ends, and an upper pair of apertures 233 of identical shape in vertical alignment therewith. When the rear shutter is cocked the rounded right edges of the apertures register with the selector plate openings 172 or 173, depending upon the position of the selector plate.

"The front shutter 235 rests in face-to-face relation with the rear shutter in the guiding grooves previously described, the straight upper edge being in engagement with both upper guides and the lower edge being provided with a straight portion 236 for engagement with one lower guide and a slot 237 for engagement with the other lower guide. The front shutter is provided with a longitudinally extending notch 238 near its lower right end into which extends the lower acuating spring 240, the opposite end of which is connected to a pin 241 on the cover 11.

The shutters are made of thin spring steel and weigh substantially the same amount, and the springs 227 and 240 are or" substantially equal strength, so that when the shutters are released they will move across the camera at substantially the same speed. The rear shutter is provided with a nose portion 242 along its lower half and the front shutter is provided with a nose portion 243 along its upper half, the edges thereof being engageable with a fiber strip 24-4 mounted at its ends in supports on the cover 1.1 so as to be capable of springing slightly to cushion the shock of arresting the shutters at the limit of their travel. The nose portion 243 strikes the upper end of the arresting strip 244, and nose portion 242 strikes the lower end of the strip so as to minimize rebound of both shuttors.

The front shutter is provided with a slot 246 through which the selector plate shifting shaft extends, and is pro vided with a single pair of vertically aligned apertures 2 57 and 248 similar to the apertures 232 and 233 but reversed so as to have squared ends at the right and rounded ends at the left. The distance between the left edges of each pair of openings 232 or 233 is the same as the distance between the right edges of the openings 247 and 243 and the vertical left edge 249 of the front shutter. When the shutters are in released position the vertical edges of apertures 247 and 248 and the edge 249 of the front shutter are at the right of the selector plate apertures 172, as seen in Fig. 9, and all of the apertures in the rear shutter are well beyond the apertures 172 and in approximate alignment with the apertures 173. When the shutters are in cocked position the vertical left edges of apertures 232 and 233 are at the left sides of the apertures 1'72 and solid portions of the front shutter block the passage of light therethrough.

The shutters are supplied with resetting lugs, 25%) and 251 respectively, which are relatively superimposed when the shutters are in released position and when the shutters are in cocked position, the lugs being engageable by a resetting finger 252 (see Fig. 13) on a resetting lever, to be described, whereby the shutters may be moved from released to cocked position upon each film advance. The rear shutter is provided with a vertically extending, secondary latch engaging, vertical edge 253 which is engageable with a secondary shutter latch 254 capable of holding the rear shutter in set position independently of the front shutter. The rear shutter is also provided with a spaced, vertical edge 255 which is engageable with a primary shutter latch 256. The front shutter is provided with a single, vertical, primary latch engaging edge 257 which is aligned with the edge 255 when the shutters are released as seen in Fig. 9, or cocked as seen in Fig. 13, so that both shutters may be held in cocked position by the primary shutter latch 256. The primary shutter latch 256 is released to initiate an exposure and, since the front shutter is held solely thereby, the front shutter will speed across the front of the camera and come to rest with its apertures in alignment with the windows 17%. At a time interval subsequent thereto the secondary shutter latch 254- is released so that the rear shutter will speed across the front of the camera and come to rest with its apertures out of line with the windows 170. The time interval between release of the front and rear shutters determines the exposure time during which light passes through the windows, both shutter blade apertures and lenses. For bulb exposures the front shutter is released and comes to rest, in which case the aperture 247 or 248 is i4 opposite one of the lenses and the straight edge 249 has cleared the other lens. The rear shutter is held in cocked position with the apertures 252 and 233 in alignment with the lenses so that light may pass through the unrestricted apertures until the desired time has elapsed, whereupon the secondary shutter latch 254 is released to permit the rear shutter to travel to released position, thereby blocking the passage of light to the lenses. When the shutters are reset they travel together in the same relationship illustrated in Fig. 9 and remain in the same relationship in set position so that light blocked until the next exposure is desired. This structure is essentially the same as that illustrated and claimed in my aforesaid copending application, Serial No. 754,961, new Patent No. 2,553,051.

Both of the shutter latches 254 and 256 are provided with sharply beveled, pointed ends so that when the shutters are released and swing the latches back the pointed ends will be in position to engage a pair of tongues 258 and 259 which project from the front shutter beyond the rear shutter in spaced relationship to the latch engagin edges 255 and 253 thereon. When the resetting lever is actuated to move the shutters from released to cocked position the tongues force the shutter latches to swing about their pivots, thereby causing the latches to return to their holding positions.

The shutter resetting finger 252 comprises an extension of a resetting lever 2651 (Figs. 11 and 13). The resetting lever 265 is supported upon a timer and resetting mechanism mounting plate 266 which extends horizontally across the lower portion of the frame in a space provided beneath the bottom of the light tunnel clearance holes 63, the plate being supported by suitable mounting means including screws 26'? and spacing collars 26$ surrounding the same, which screws pass into threaded openings in the bottom of the frame (not shown), a screw 269 at the front which is held in spaced relation to the bottom of the sprocket cavity by a spacer 2'70, and by a tongue 271 projecting longitudinally and wedged between a pair of lugs 272 projecting forwardly from the outer surface of the cartridge cavity 4-2. The lever 265 is provided with a slot 275 which is substantially in the shape of a long, narrow ellipse and into which projects a guiding lug 276 comprising the head of a rivet set in plate 266. The end of lever 265 away from the finger 252 is provided with a pair of upwardly projecting, hooked flanges 277 between which there is an open slot indicated at 278. The lever 265 is provided with a depending guide pin 280 which projects through a longitudinal guide slot 281 in the plate 266, the pin engaging the hooked end of a spring 282, the other end of which is anchored to the screw 269, the spring thus tending to hold the shutter resetting lever 265 in the position illustrated in Figs. 11 and 13 with the lever being maintained against the guiding lug 276. In this position the hooked flanges 277 are engageable by one or the other of a pair of driving pins 285 diametrically opposed to each other on an hourglass-shaped cam 286 fixed to the lower end of the sprocket gear shaft 56. When the sprocket gear is rotated in either direction the pins 285 successively engage one of the hooked flanges 277 and drive the finger 252 toward resetting position. Engagement of the pins 285 with the flange 277 will occur throughout the greater part of a half revolution as the lever 265 and finger 252 move the shutter blades to reset the position, but when the half revolution of the sprockets is nearly completed the pin 285 will pass through the slot 273, permitting spring 282 to snap the resetting lever back to its initial position in readiness to engage the shutters when released the next time.

Shutter latching and release mechanism The hourglass cam 236 (Fig. 13) is in position to engage an end of a driving lever 290 which is journaled on a timer cam hub 293 which, in turn, is journaled in the plate 266, the lever having an oppositely extending end 292.

A peripheral groove in hub 293 loosely retains a hairpin driving spring 294 bent around the groove with one end hooked about a floating lever driving pin 295 fixed in the lever end 292. The other end of the hairpin-shaped spring 294 hooks into an ear 297 on a driving lever release pawl 298 which is pivotally mounted on a pivot 299 mounted on the plate 266. The spring is so tensioned as to tend to rock both the pawl 29% and the driving lever 290 counterclockwise (Fig. 13). The driving lever release pawl 293 is provided with a downwardly turned end flange 3% which engages the front edge of the extension 292 of the driving lever to lock the driving lever in the cocked position illustrated in Fig. 13. The release pawl is provided with a downwardly turned flange Still which is engageable with a release lever 3%, also pivoted at 299.

The release lever is normally maintained in the relation shown in Fig. 13 by a spring 303 hooked into the end of a downwardly turned flange 3% on the lever and anchored to a suitable portion of the frame (not shown), the spring urging a projection 3&5 on the release lever against a stop 3% projecting downwardly from the frame Ill. The release lever is provided with an arm 367 bearing against the surface of plate ass to keep the lever parallel to the plate. The release lever may be rocked clockwise from the illustrated position by pushing inwardly on a release button 3&3 in a recess in the front cover and fixed to the end of a release push rod 3G9, the rod being slida'bly guided in the front cover lll. The inner end of the rod is bent upwardly at 310 in such fashion as to be engageable in a small opening in the release lever, the connection being such that when the front cover is unfastened from the frame the hooked end Sill may be disconnected from the release lever in order to permit removal of the front cover. When the release button is pushed inwardly the release lever is rocked clockwise, thus pushing against the flange Frill on the release lever pawl to rock the release lever pawl clockwise about its pivot 299, thereby removing the flange Silt] from engagement with the front edge of the driving lever and permitting the hairpin spring 294 to move the driving lever counterclockwise. As soon as counterclockwise motion of the driving lever commences the end edge of the portion 292 engages the outer surface of the flange 300 to lock the driving lever release pawl 295 in releasing position until resetting action is completed, in spite of the fact that the button 3% may have been released to permit the release lever to be returned to its normal position by spring 393.

The driving lever release pawl 29% is provided with a forked arm 315 which embraces the rounded end of a slide lock shaft actuating lever 316 fixer. to the lower end. the slide lock shaft The lever 316 is in line with the slide lock 145 (Fig. 12) so that when the button 3% is pushed inwardly the slide lock lad is aligned with the longitudinal grooves 13% in the slides l3l, thus releasing the fceding mechanism as soon as the shutters are tripped. It has been explained that one or the other slide 131 will be moved longitudinally during the first few degress rotation of the sprocket driving gear 58 (as driven by the knob Eli) and then returned to its initial position by the spring 137. When the driving lever is released the lower end of pin 29 5 strikes the edge 2% of the plate 266 which acts as a limit. Also, the arm 2% rocks to a position close to the hourglass earn 256. Boring approximately the first quarter turn of the sprockets and cam the lever is rocked clockwise by one of the four curved faces of cam ass. During approximately the iirt sixty degrees rotation of the hourglass the flange 3th; on the release pawl is engaged with the end edge of the extension 292 on the driving lever so that the release pawl is maintained in position such as to hold the lock 146 in alignment with the slots fill. Following the return of the actuating slide 131 the flange 36H? is released,

thus permitting the driving spring 294 to snap the release pawl back to the position illustrated in Fig. 13 with the flange 3491 acting as a limit, thus immediately rotating the lock 146 to the position illustrated in full line in Fig. 12 to prevent further movement of either of the slides 131. When the release pawl 298 is thus snapped back the flange 309 re-engages the front edge of lever arm 22 to hold the driving lever in the position illustrated in Fig. 13 after the earn 286 leaves the arm 2%,.

The primary shutter latch 256 is pivotally mounted on plate 266 at 32% (Fig. 13) so as to be capable of swinging from the latching position illustrated to a released position in which it bears against a tab 321 struck upwardly from plate 266 (Figs. 11 and 13). it is held in latching position by a primary shutter latch pawl 322 pivoted at 323 and urged clockwise by a spring A releasing lug 325 on the driving lever 29% engages a cam portion 32s on the pawl to disengage it from the latch at the proper instant, this instant remaining constantly fixed regardless of the shutter timing. When the resetting lever 265' moves the shutter blades to the reset position, tongues 25% and 259 of shutter blade 235 engage latches 255 and 254, rotating them counterclockwise to the reset position shown. When tongue 2:78 rotates the latch 256 to the reset position,,pawl 3122 hooks over the latch to bring portion 326 into contact with lug 325 of lever 29%.

The secondary shutter latch 254- is pivotally mounted at 330 and is held in latching position by a hook 331 (Figs. ll and 14) on an arm of a floating lever 3552. under plate 266. The hook 331 is normally maintained forwardly, as seen in Fig. 14, by a spring 333 anchored to a pin 334 projecting downwardly from plate 266 and hooked over a pin 335 projecting in both directions from the floating lever, the upper end projecting through an opening 336 in plate 266 (Fig. 13). The lower end of pin 335 is rounded (Fig. ll) so as to slide freely over the upper surface of an escapement mounting plate 337 held in spaced relation to plate 266 by screws 338, 339 and 341i and surrounded by suitable spacer sleeves (Fig. 14). When hook 351 is displaced rearwardly from the position illustrated in Fig. 14 the secondary latch 254 is released to permit the rear shutter 225 to move to released position, the latch swinging against pin 334- where it remains in position to be returned by tongue 259 on the front shutter 235 at the next resetting operation. During the resetting action the hook 331 is brought back to bear against the cam face 341 on the secondary latch, the cam face slightly displacing the hook rearwardly until it can be snapped into holding position by spring 3.

Shutter timing The timer cam shaft 29 extends above the feeding gear trains (Fig. 11) and is provided with a driver tip 359 which slidably engages in a driving slot (not shown) in a timing adjustment dial 351 (Fig. 2) journaled on the top cover 18. The dial is provided with indicia designating fractions of a second and the word Bulb, any selected indicia being positionable opposite a fixed pointer 352 on an exposure indicator cover plate 353. As the dial is rotated shaft 291 rotates a timer (Figs. ll and 14-) beneath plate 266. The timer cam is provided with a spiral edge 356 and a reduced section 357 of relatively small radius, the spiral face corresponding in extent to the numeral bearing portion of dial 351 and the reduced section corresponding in extent to the word Bulb. Any point on the cam corresponding to a selected point on the dial may thus be positioned in operative alignment with a fulcrum portion 334"; on the floating lever 332. When the driving lever is released the spring 294, operating through the pin 2%, and the spring 333, cause the nose of fulcrum portion 33% to move forward into engagement with cam 355, the rounded lower end of pin 335 sliding over the surface of plate 337 to permit such movement. When the cam arrests forward movement of the fulcrum portion the pin 295 and the adjacent end of the floating lever continue to move for ward, thus pivoting the floatirzg lever to move the hook 331 rearwardly from engagement with the secondary latch 254 to release the rear shutter 225. The fulcrum portion 380 may only engage the spiral portion 356, the release of the latch occurring soonest when the fulcrum engages the greatest radius portion thereof, and progressively later as the spiral decreases in radius.

In order that the releasing action may be timed accurately, the floating lever is connected to an escapement mechanism as follows: An escapement sector gear 382 is pivotally mounted at 383 on plate 337 and carries a sector gear pin 384 projecting upward into a slot 385 in the floating lever. The teeth of the sector gear mesh with a pinion 386 on shaft 387 journaled between plates 337 and 266 and fixed to an escapement ratchet 388. An escapement pawl 339 is pivotally mounted on plate 337 in position to engage and release the teeth of the ratchet as it is rotated by the hairpin spring 294 operating through the driving lever 290 and the sector gear 382. The spiral of cam 355 is such that when the fastest exposure is required the floating lever 332 pivots and releases latch 254 just after pawl 322 (Fig. 13) releases latch 256 and pawl 389 rocks over a minimum number of teeth. As the radius of the spiral decreases the pawl 389 must rock a progressively increasing number of times before the hook 331 releases pawl 254, thus increasing the time interval between release of rear and front shutter blades, and of the film exposure.

Bulb action When the section 357 of cam 355 is effectively aligned with the fulcrum portion 380 of the floating lever the fulcrum 38% can never contact the cam to release the secondary latch since the floating lever is arrested first by the pin 295 (Fig. 11) engaging the forward edge of Opening 2% in the plate 266. Therefore, one shutter is released and comes to rest while the other shutter remains cocked, thus opening the apertures for timed exposures. This condition continues as long as the release button is held, but when it is permitted to return to its normal position the inner shutter is released as follows: The pin 335 (Fig. 13) is moved forward toward the front of opening 336 as the escapement is released, thus placing the pin in the return path of an extension 390 of the release lever 302. When the button is returned to its normal position by the spring 303, the extension 390 engages the pin 335 (Fig. 13) and the pin then becomes a fulcrum causing lever 332 and hook 331 to release latch 254 and terminate the exposure.

Diaphragm adjustment The exposure indicator cover plate 353 also partially covers a diaphragm knob 409 (Fig. 2) which carries a plurality of aperture size indicia movable past a pointer 461. The dial is fixed to the upper end of a diaphragm pinion shaft 402 (Figs. ii and 12) journaled in the top cover it and the frame it A pinion 403 on the lower end of shaft 432 meshes with teeth on a diaphragm rack 464 guided for longitudinal movement on top of frame beneath the feeding gear train by a pair of guide pins 405 and 4% engaging slots 407 and 408 respectively, in the rack. The rack is provided with a large open eye 410 at one end which communicates with slot 408 so that the driver head 35:! on the timer cam shaft 291 may be re moved with the shutter escapement assembly when the rack is moved to one extreme position. The rack is provided with a pair of claws 411 which embrace a vertical extension 412 on a diaphragm yoke 413 extending across the front of the frame 1-5 (Figs. 11 and 12). Pivots connect the ends of the yoke to a pair of diaphragm levers 414 which extend through slots 415 in the lens barrels 416 and are operatively connected to iris diaphragms 417 (Fig. 5) in the usual manner. When the rack is moved the diaphragm openings are adjusted in,

18 accordance with the dial setting. The extension 411. slides vertically in the claws 411 as the light tunnels 64 are shifted as previously dearibed. The yoke 413 is in front of the tunnel shifting yoke 193 so as not to interfere therewith, and the yoke 413 is upwardly curved at its middle so as to clear the selector plate shifting pinion T83 when lowered.

Exposure indicator The central portion of top cover 18 comprises the housing for an exposure indicator such as disclosed and claimed in my aforesaid Patent No. 2,557,478. The timer dial 351 and the diaphragm knob 4th) comprise portions of the indicator which cooperate with and actuate a film speed selector dial 420 through mechanism (not shown) as illustrated in said patent. The shaft to which dial 420 is fixed by a screw 421 loosely journals a light intensity dial 422 which is frictionally rotated by dial 424 or which may be slipped around by manual actuation. The dial 421 carries a Winter reference mark and a Summer reference mark, either of which is used according to the season. The dial 422 carries one group of indicia representing film emulsion speed, one of which is to be manually aligned with the proper seasonal reference mark on dial 429, the selection depending upon the film being used at the time and the aligning being accomplished by manually slipping dial 422. The opposite side of dial 422 carries a plurality of legends and reference marks representing diiferent degrees of light intensity. Proper rotation of either the timer dial 351 or the diaphragm knob 40%, or simultaneous rotation of both, will cause dial 420 frictionally to drive dial 422 until the proper light intensity reference mark on dial 422 is aligned with the proper one of a plurality of Subject Color reference marks on the cover plate 353. The dial 351 and knob 4% are prevented by suitable stops from rotating beyond the limits of the scales thereon. if the proper light intensity and subject color marks cannot be made to align for a desired shutter speed or diaphragm opening, the operator is thus advised that the picture would not be well exposed and that he must compromise on one or the other to have a good exposure. If alignment cannot be achieved in any fashion the operator should wait for a brighter day or take a Bulb exposure. In many instances alignment can be achieved in a wide variety of combinations of shutter speed and diaphragm opening, in which case selection may be determined by some factor such as the speed of movement of the subject as in photographing sporting events. Regardless of how the dials are manipulated to achieve alignment, the cam 355 and the diaphragms 417 will automatically be in readiness to effect a proper exposure.

A feature not found in the above-identified patent is herein disclosed, comprising depth of field indicating means associated with the diaphragm adjusting dial 4%. It will be observed that the dial carries a plurality of indicia representing distance, which are rotatable past an edge of the plate 353 indicated by the reference character 425. The plate 353 preferably carries a suitable legend to the effect that any object between the distance indicated by the edge 425 and infinity will be in clear focus, a situation made possible by the use of universal focus lenses.

F lash synchronization A switch for operating a flash attachment is provided on the front cover 11 (Figs. 9, 10, 18, 19 and 20) in position to be operated by the front shutter and related mechanism. The switch comprises a rigid contact bar 43% carrying a fixed contact 431, the bar being mounted on an insulator block 432 by a pair of insulated screws 433 threaded into a lug on the cover. The fixed contact may be contacted by a movable contact 434 on a spring contact bar 435 having tension upward, and electricaily grounded to the plate 11.

A spring switch actuator 440 is mounted adjacent the spring contact bar 435 with tension downward, and is provided with a hook 441 (Fig. 9) extending over the tip of spring contact bar 435. Downward tension of actuator 440 is suflicient to overpower upward tension of spring contact bar 435 and the actuator normally holds spring contact bar 435 down against a finger 436 on plate 266.

Tab 258 (Fig. 10) of the front shutter 235 is in operational alignment with a tongue 443 on actuator 440 so that when the shutter 235 is in released position *tab 258 wedges between tongue 443 and a rounded boss 442 on the front plate 11 to move actuator 440 (Fig. 19) up and thereby permit spring contact bar 435 to close the contacts 431 and 454. In this way the switch is closed at the instant the front shutter blade reaches its released position whereat light is permitted to reach the lenses.

An arm 437 (Figs. 18 and 13) on the release lever 302 normally engages spring contact bar 435 to hold the contacts open, this action being independent of the action of actuator 440. The arm 437 moves to inoperative position (Fig. 19) only when the release button 308 (Fig. 13) is depressed, at all other times holding contacts 431 and 434 (Fig. 18) apart. In this way, the arm permits the shutter 235 to close the contacts when the picture is taken, but opens the contacts as soon as the release button 308 is permitted to return to its normal position by spring 303 (Fig. 13). Thus the flash circuit is rendered safe and new :flash-bulbs may be inserted in the flash unit safely at any time, with the camera shutter cooked or not.

A flash contact wire 445 is soldered to the fixed contact bar 430 and runs along the base of the front cover 11 above lugs 27 (Fig. 9). It is suitably secured to the end of the cover (not shown) and led up through its light trap flange 446 (Fig. 12), its end being soldered to a plate 450 mounted on the upper end of shaft 127 (Figs. 6 and 21). The plate is held in position by a pair of insulator washers 451 and 452, a screw 453, and metal washers 454 and 455, the washer 451 having an interlocking step to insulate the plate from the screw. The plate is made of spring material and has a contact finger 45% extending therefrom into contact with the edge of a contact washer 459 mounted in the top cover 18. The washer 459 is held in position by a contact rivet 460 (Figs. 2 and 21) extending into a socket 461 in the top cover and insulated therefrom by fiber washers 462 and 463. The socket 461 is near a screw socket 464 in which a flash gun connector (not shown) may be engaged, the gun being thereby grounded to the frame. appreciated that the gun will have a second projection insertable into socket 461 to make contact with the tip of rivet 460.

Viewfinder A viewfinder lens cover 470 (Figs. 21 and 26) is retained against suitable flanges, such as flange 471, in the top cover 18 by a pair of slotted head nuts 472 engaging studs imbedded in bosses 473. The cover 470 is provided with suitable openings through which the driver head 350 on timer cam shaft 291 and the diaphragm adjusting pinion shaft 402 project. The middle of the support is trough-shaped to provide a tunnel leading from an eye opening 475 (Fig. 26) in the rear of the top cover 'to a sight opening 476 (Figs. 1 and 26) in the front of the top cover. A spring lens retainer 477 is mounted in the trough, being held in spaced relation to the recessed portion of the top cover in which the dials 351 and 400 are seated, by a slotted spacer rivet 478 engaging a longitudinal slot 479 in the front of the retainer, and a bridge 480 spanning the bosses at the rear. A pair of legs 481 depend from .the front end of the retainer 477 and straddle a square lens 483, the legs engaging the sides of the lower portion of the lens and being provided with lugs 482 which press against the rear of the lens, the lens being thus retained in a seat provided in the cover '18. similar pair of legs 484 joined at their extremities by a crosspiece 485, embrace the edges of a circular lens 436.

It is to be to retain it in position at the eye opening 475. The space between the retainer 477 and the top cover is available for the exposure indicator mechanism, a journal opening 496 being provided in a boss 487 in the cover through which the shaft (not shown) supporting dials 420. and 422 extends. The lower edge of opening 476 is open and the lower portion of lens 483 and the forward edge of the viewfinder cover 470 project into the space be tween a vertical light trap flange 488 and a horizontal light trap flange 489 on the front cover 11, the flange 488 being notched at 490 (Figs. 1 and 9) to define the lower portion of the sight opening. The forward portion of cover 470 is provided with a transverse well 491 in which is cemented a spirit level capsule 492, the capsule being out of the line of sight through the viewfinder but constantly visible when looking through the viewfinder.

Relase cable mechanism Fig. 20 illustrates an improved release cable mechanism which is built into the camera, comprising a plunger 500 having its outer end normally resting flush with the bottom of the depression in the front cover 11 in which the release button 308 is located. The plunger is maintained in alignment with the flange 304 on release ilever 302 in suitable bores through a portion of the front cover 11, the :flash synchronization switch mechanism including the switch members 430 and 435, the switch actuator 440, and the bracket 499. The bracket 499 has a forwardly extending arm 501 having an end flange guiding the inner end of the plunger 500. An intermediate portion of the plunger 500 is provided with an annular recess in which is seated a split ring 502 forming a retainer for one end of a compression spring 503, the other end of which bears against the upwardly extending flange of the arm 501. The plunger may be moved forward to contact the flange 304 and swing the release lever 302 until the flange strikes a limit abutment 504 on the frame 10. The outer end portion of plunger 500 is normally located within a threaded recess 505 into which may be inserted the threaded end of a release cable connector 506, thereby positioning the end of a flexible release wire 507, retained in a flexible sheath 508, adjacent the outer end of the plunger 500. The Wire 507 and the sheath 508 constitute a flexible release cable, the opposite end of which supports a release mechanism operating button or the like (not shown) of any desired type for the usual pur poses of such devices. The present invention is an improvement over any similar construction heretofore devised in that the plunger 500 closely fits the bore in the cover 11 inwardly from the threaded recess 505 so as to provide a dust seal for preventing the entry of foreign material into the camera. The length of the portion of the plunger which is guided in the switch mounting assembly is such that the outer end portion of the plunger is always maintained within the bore so that even though foreign material should collect on the outer end of the plunger it may not be carried into the interior of the camera when the release cable is actuated.

Pressure pads and pressure springs In Figs. 7 and 8 it may be seen that the inner surface of the rear cover 12 supports a pressure pad and pressure spring mounting plate 520 which extends substantially from end to end of the cover, the ends thereof being bent toward the cover to prevent catching the film. The pad is supported by a longitudinally spaced pair of shoulder rivets 52 1 located substantially along the longitudinal center line and a pair of intermediate, laterally spaced rivets 522 surrounded by spacers 523. The rivets 522 hold a connecting portion of a pressure pad mounting spring 524 against the surface of the piate 520, the spring having a pair of longitudinally projecting pressure pad mounting arms 525 projecting toward the cartridge receiving space and bent outwardly from the plane of the. mounting plate at their intermediate portions. The op-' 

